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Current time:0:00Total duration:9:53

Video transcript

if we want to understand where we've come from the stories that have led us to our present condition if we want to understand our history one of the prerequisites is to have a good sense of chronometry and chronometry very fancy word but it really is just the science of the passage of time chrono really relating to time metree time measurement and we take many many things for granted these days we assume that we know what happened the last 50 years the last hundred years and now we're starting to assume we know what happened ten thousand years ago or what happened to our planet 100 million years ago or a billion years ago but these are all very very very new phenomena this this ability to kind of to kind of shine a light on the past and even the traditional notions of history the traditional stories of what led to what the political nations that formed the migrations of people and when they happened that traditional notion of history is even fairly new when you think about just the scope of of how long we think humans have now been on this planet and that first that traditional notion of history you can kind of use the first chronometric revolution and that first chronometric revolution revolution that gives us that that this kind of traditional notion of history really just comes out of humanity's ability to write so the first so writing writing gives us our first chronometric revolution because this was the first time even though we think humans or human-like creatures have been around for hundreds of thousands of years at this point they didn't they weren't able to keep their stories in a very in a very exact way they might have had an oral tradition it might have gone from one generation to the other but those oral traditions things would get lost and the most important information would get lost is how long ago to these stories start up and you we weren't able as a species to really have a firm understanding of when things happened and how long ago things happening happened until until writing became mainstream and until writing was done in a way that it became permanent and our best sense of when this happened the first time was by the Sumerians with cuneiform and this happened right around the 3rd millennia BC so around 5,000 years before the present time and this is what some of that earliest writing looked like this is actually a letter from I believe a this is from a king and you could see it's it's just it's just highly symbolic carvings this is what we more traditionally associate with cuneiform and it was symbolic based as opposed to now most of our languages are based on phonetics which kit so you have fewer symbols that can represent more meetings but this was a huge technological revolution I could say for Humanity because now with the advent of cuneiform you a now had permanent writing that someone could look at a thousand years later 2,000 years later and if they can decipher the cuneiform they can get a written testimony of what was happening at that time and they didn't have to rely on an oral tradition or even guess when that oral story might have started but writing is since it'll only happened about 5,000 years ago so this is 5,000 5,000 years before before the present or you could say 3,000 years 3000 years BC give or take that was a start but this only gave us stories of about 5,000 years old and even then it was a very spotty historical record we didn't really get really deep history depending on where you are in the world until really the last few thousand years but it was a start this was the first chronometric revolution but what you may or may not realize is that we are frankly I believe at the very early stages of another chronometric revolution that has that has really just begun to accelerate in the last 50 60 70 years and this second chronometric revolution ii ii chronometric revolution I should write revolution up here - this was a revolution it allowed us to keep time in a permanent way to understand things to not have to talk to the people to whom something happened we can see their written testimony of it but the second revolution really comes out of the advent of a lot of our understanding of modern science so in the 1800 1800 s you have radioactivity gets discovered by Marie and Pierre Curie so this is 1900 right here so this is relatively recent remember we're talking about a species in a bit that has been around for several hundreds of thousands of years and protohumans have been around for millions of years and now only 5000 years ago at least as far as we know was the first writing and then only little over a hundred years ago was a discovery of radioactivity so radioactivity and then the ability to use radioactivity so radioactivity is interesting is this idea that essentially elements can change from one variation to another of an element over long periods of time so through radioactivity so they become kind of this natural clock we didn't know one had to go there and and set up a timepiece for it that that luckily there are these things that decay at a very predictable rate so we discover radioactivity a little over a hundred years ago and then over the course of the 20th century we got better and better more sophisticated at really understanding radioactivity to be able to use it to measure the times of things and if you're fast forward to the second half of the 20th century so now if we're at nineteen fifty this is where the second chronometric revolution really took hold this is where it really took hold where we started to understand carbon-14 dating we started to understand some of the other techniques that we talked about is we can start to date older and older things and what I want to be clear this was the radioactivity the understanding of radioactivity was just the beginning of this second chronometric revolution the second chronometric revolution which frankly we are still a part of isn't just radioactivity it's also understanding the expansion of the universe the constancy kind of the speed limit of light that now let's just figure out wow that that background radiation we're getting that must have been that must have been traveling for 13.7 billion years ago so we can now look at evidence from our from our environment and our environment is not just the earth itself it's it's it's radiation bombarding us from space that allows us to make that gives us clues as to not just the age of us as who of humanity the age of species the age of the planet but the age of the universe itself so it isn't just about radioactivity radioactivity is a big part of our chronometric revolution this is what allowed us for the first time you know if we have layers on the earth people have known for a long time that if we assume that these layers haven't been jostled that something at a lower layer down here is probably going to be older than a opéra layer because year after year you have deposits if it hasn't been messed up in some way but no one knew they said okay well this is relative dating this this is older this is younger but we had no way of knowing that hey is this a thousand years old or is this a million years older is this a billion years old but now with radioactivity now we could start to say hey we can date some of the rocks here that are 150 million years old and some of the rocks here are about 100 million years old so maybe this fossil of a fish that we're finding or this primitive fish like creature right over here this would be between 100 and 150 million years old and the only way we're able to do this was with with with being able to date things using radioactivity but radioactivity is just to start as I mentioned we're getting better and better understanding of cosmology we're getting better measurements of the universe itself we're understanding physics at a deeper level now we can start to look at the genome and think about how the genome diverges from one species to another and how quickly it changes so all of these things are just allowing us to get better and better refinements on the chronology obviously this is a start but you still don't know plus or minus 15 million years how old this is and how this relates to other things that you might find so I just wanted to point this out that that what we take for granted now the age of the universe the age of Earth at four and a half billion years old humans being around for several hundreds of thousands of years this understanding is a very very very new phenomenon it's due to the second chronometric revolution that I think we are still a part of and even the first chronometric revolution this version of history and I want to be clear history was limited by this first chronometric revolution it was limited by whatever was documented but now maybe we can expand our notion of history and there's a lot of the videos that I've been working on have been for this big history this big history project which says hey before history was limited by the first chronometric revolution to what was written by what was testified by people and was made permanent in some way now we have chronometry has taken us so that we can understand things into our deep past before even the earth has existed so why not redefine history in a big way for it to encompass everything for it to be big history anyway I'll leave you there and actually I want to also emphasize that I'm you know the the second quarter metric revolution is a big deal allows us to transform even our understandings of history but even this first chronometric revolution right over here 5,000 years is still not very long in the entire scope of even even human civilization